-- auto cast type
print(10 .. 20) 	-- output a string: 1020
print("10" .. 20) -- output a string: 1020

-- use function to cast type
print(type("   -3   ")) 					-- string
print(type(tonumber("  -3  "))) 	-- number
print(tonumber("100101", 2)) 			-- specifies the base of the casting number
print(tostring(10)) 							-- 10
print(type(tostring(10))) 				-- string
print(type(tostring(10)) == "string") 	-- true
